The invention relates to mattress-supporting box springs, and more particularly to an improved, simplified box spring construction wherein sway is eliminated.
In the past most box springs included a wooden framework bottom, with an array of springs arranged in rows and connected to the framework bottom by staples or other fasteners. In a twin bed size box spring, depending upon the size of the individual springs used, a pattern of as many as nine rows of five springs each, or 45 springs, may be included. The springs of the array were generally tied together at their upper ends by wires, bands, springs or other connectors to maintain each spring in its proper position relative to the other springs during compression of various areas of the spring array. Often a stiff, heavy wire was included around the upper periphery of the box spring, perhaps connected directly to the outer edges of the top of the outermost springs in the array to define the upper edges of the box spring and to add to the rigidity of the spring array. Many such box spring assemblies were then supplied with a layer of padding material over the springs, and a fabric cover material completed the assembly.
Besides requiring such a large number and area of springs, such prior mattress construction also had the disadvantage of swaying considerably in response to side and end forces, often causing discomfort of those occupying the bed and a general instability of the bed. This swaying occurred because there was nothing rigidly securing the springs of even the heavy peripheral wire member against horizontal movement with respect to the lower framework. Thus, the tops of the springs were free to deflect horizontally as well as vertically. In addition, such construction was often relatively expensive because of high labor requirements in affixing the springs to the wooden framework, particularly with such a large number of springs, and also because of other inefficiencies of construction which significantly contrast with the box spring of the present invention described below.
In the prior art, U.S. Pat. No. 692,535 shows a seat spring and supporting member connection which is somewhat similar to the spring connection of the present invention. However, as will be seen below, the connection of that patent is considerably more elaborate than that of the present invention, being designated to give the spring upright stability as well as load support. The simplified connection of the present invention is not depended upon for such stability, other anti-sway means being provided.